Grouting process and apparatus



July M', 195i L. s. WERTZ 2,560,619

GROUTING PROCESS AND APPARATUS Lbus S., Werz ATTORN EY July 17, 195 L s, WER-:VZ 2,560,6l9

GROUTING PROCESS AND APPARATUS Filed May 22, 1948 2 Sheets-Sheet 2 E lli;

I "uw INVENTOR Lamis S. Wevz BY v01@ ATTORNEYS Patented July 17, 1951 S PATENT OFFICE GROUTING PROCESS vAND APPARATUS Louis S. Wertz, Cleveland, Ohio Application Max/'22, 1948, Serial No. k28,710

7 Claims. 1

This invention relates to apparatus for and the process of constructing concrete and/or masonry structures, and in particular to structures which are more nearly monolithic and solid or dense than structures erected according to present day practices.

It is an object of the present invention to provide an apparatus for 'and process of erecting structures by enclosing 4a mass of aggregate in the form of the desired structure and then forcing a suitable grout composition into the voids and interstices between individual pieces of aggregate in which the complete structure may be substantially continuously filled with such grout in a continuously rising horizontal level.

Another object is to provide apparatus for and a process of erecting structures by forcing a grout composition into the voids and interstices between individual pieces of aggregate placed within a cavity enclosed by surfaces which dene the desired structure which 4will insure a more complete filling of such voids and interstices and will thus result in a more solid, dense and stronger structure.

A Vfurther object of the present invention is to provide apparatus for and a process of erecting concrete or masonry structures of the type described above in which the forcing of the grout may be accomplished on a selective and controlled basis so that the structure is grouted su-bstantially simultaneously throughout in progressively rising horizontal strata, thus resulting in a more truly monolithic structure than if portions or areas of the structure were separately grouted.

A further object is to provide apparatus for and a process of erecting a concrete or masonry structure of the type described above in which the structure may be substantially completely grouted at one time without stopping, thus accomplishing automatically the securing together of individually grouted portions to obtain a true monolithic structure.

Another object is to provide apparatus for and process of grouting in which the grout is forced through a closed conduit which begins and ends at a source of supply of the grout, so that the grout may be withdrawn at predetermined locations along said conduit and selectively forced into various portions of the structure as desired, such forcing of the grout being controlled to produce a substantially monolithic structure.

Other objects and advantages will become apparent from the following detailed description accompanied by the drawings, in which:

Figure 1 is a diagrammatic plan view of a 2 structure being erected in accordance with the present invention;

Fig. 2 is a 'diagramma-tic elevational view, partly in section, vof the structure shown in Fig. 1 taken substantially on line r2 2 of Fig. 1;

Fig. 3 is an enlarged elevational view of a portion of the structure shown in Figs. 1 and 2 with par-ts broken away, to further illustrate details of the process and apparatus; and

Fig. 4 is an enlarged `fragmentary sectional view of a portion of the interior of the 'structure during grouting thereof;

Fig. 5 is a detail view 'of one of the pumps showing hose line connections thereto.

Briey, a prefer-red embodiment of the present invention comprises dening a cavity which has the size and shape lof the desired structure, filling the cavity with aggregate, embedding a plurality of tubular members or casings apertured at spaced intervals to permit communication with the cavity, combining predetermined quantities of ingredients for a suitable grout mixture, thoroughly mixing such ingredients, `forcing the mixed grout through a Vconduit disposed adjacent the cavity, preferably returning the conduit to the mixing apparatus so that tgrout is continuously flowed through the conduit, selectively Withdrawing .grout from the conduit at predetermined intervals therealong, and selectively forcing the grout so withdrawn into certain of the casings and thence into the `cavity to ll the voids and interstices between individual pieces of aggregate and controlling the flow 'of grout so that the grout level in the cavity progressively rises in substantially horizontal planes.

I-t has been found that erection of structures in this way results in a more complete filling of the spaces between individual pieces of aggregate and that the placement 'of the grout in the manner .described permits it to set and form a continuous integral grout network. Structures thus erected have a solid dense Vinterior and are more nearly -monolithic than present day Socalled monolithic structures since grouting may be continuously accomplished without joints between individually 'constru'cted portions. The resulting structure is stronger, more durable and has lgreatly increased weatherresistant properties, being substantially impervious to moisture. seepage and the like which tend to disintegrate and erode a structure.

4It 'will be obvious as the description progresses that the term structure as utilized herein includes the erection' of 'new structures as Iwell as the erection of additions' or the replacement of portions of existing structures and thus the surfaces enclosing the cavity which define the desired structure may be provided by form Walls constructed of Wood, precast concrete slabs or any other suitable form Wall, or may equally well be the surfaces of existing structures which have been prepared to receive the addition of a new structure r portion thereof. Also a portion of such surfaces may be the earth or rock forming a part of the site at which the structure is to be built.

Erection of additions to existing structures in accordance with the present invention is highly desirable due to the fact that the forcing of grout under pressure into a cavity filled with aggregate, will not only fill the voids in such aggregate to create a solid dense structural addition, but will also, simultaneously rmly secure the addition to the original structure since the grout will flow into any voids or interstices in the existing structure which open into the cavity defined for the addition. Where a portion of the cavity is defined by rock or ground at the site of the addition, the added structure will become securely keyed or interlocked with the ground or rock at this location, supplementing the foundations which it may be necessary to provide.

For ease of illustration the drawings illustrate the erection of a structure such as a dam, pier or pile but which might equally Well be a part of or the whole of many other various types of structures.

The numeral I generally designates the cavity, which after treatment by the present invention, will become the completed structure. The sides of the cavity are defined by surfaces 2, 3, 4, and 5, which, as stated, may be suitableform walls or may be portions of existing structures which bound the cavity. For example, the surfaces indicated by the numerals 3 and 5 may be foundation walls built during preparation of the cavity for structural purposes. The bottom of the cavity is defined by the ground and bedrock at the site where the structure is to be erected. The

numeral 6 indicates the portion of the groundl which affords a form wall for a portion of the cavity, and the numeral 1 indicates rock strata which are adjacent to and dei-lne a portion of the cavity.

It may be pointed out that in preparation of the cavity the strength of the ground or bedrock may not be sufficient for supporting the structure to be erected and in this event it may be necessary to treat such areas in order to stabilize them to permit erection of the structure. This may be done by forcing a suitable grout composition into the area, which When set will solidify and strengthen the area treated. If the area is porous but of sucient strength, it may not be necessary to force grout therein prior to the grouting of the cavity as during grouting of the cavity the pressure will force grout into this area and will both solidify and strengthen the area as Well as firmly secure the structure thereto.

Where portions of the cavity boundary do not lend themselves to proper preparation by the forcing of the grout into such portion, the defining of the cavity may be accomplished by excavating such portions. Thus the cavity may be enlarged until a suitable surface is obtained or a suitable defining surface can be erected by placement of concrete footings or foundations in the excavated area.

When the cavity has been suitably defined a plurality of tubular elements or casing members 8 may be disposed therein. In the case of the structure shown these casing members are shown as being vertically disposed but it is to be understood that the disposition of the casing members may be angular or any desired arrangement which will give the proper results. The arrangement and number of the casing members 8 will depend upon the shape and volume of the structure being built, it being desirable to provide an excess of the casing members 8 so that some of them may be used for inspection purposes and also for grout delivery in the event that certain of them may become clogged orotherwise unusable.

The cavity is then filled with aggregate which is preferably placed in such a manner as to avoid segregation of the sizes. If desired, the aggregate after placement may be compacted in any suitable manner such as by the use of vibrating tools.

At the time of grouting the aggregate in the cavity may be either wet or dry. Having the aggregate wet seems to facilitate the flo-w of the grout through fine interstices and also facilitates forcing the grout under pressure for considerable distances without separation of the ingredients. A dry aggregate in the cavity being grouted apparently has the capacity for withdrawing water from the grout which tends to reduce its flowability but this may be overcome by utilizing additional water in the grout mix. Grouting may be carried on even though the cavity is immersed in water as the grout replaces water in the voids and interstices of the cavity.

Suitably disposed adjacent the site of the structure may be the apparatus for making the grout, and as shown in Figs. l and 2 of the drawings, this apparatus is diagrammatically indicated as a mixer 9 into which the predetermined quantities of suitable ingredients may be manually' or automatically fed. The mixer is operated for a suicient time period to insure a homogeneous grout composition. When this condition is achieved the grout may be fed through discharge pipe I0 to a suitable container II which acts as a reservoir to insure a constant source of supply of grout to a pump I2 through a conduit I3. The container II is preferably provided with an agitator to maintain the grout in motion and prevent setting or settling out of the ingredients. The pump I2 is provided to circulate grout through the circulating conduit I4 which passes adjacent the cavity I and returns so that the discharge end of the conduit I4 discharges into the reservoir or container I I. As shown in the drawings, the circulating conduit I4 extends across the top of the structure being erected and back.

At spaced intervals along the path of the conduit I 4 a plurality of pumping stations may be disposed at which points one or more pumps I5 may be located. The pumping stations may be selectively connected to the conduit I4 by supply pipes I6 controlled by valves Il, as shown in Fig. 3.

The pumps I5 may be of any suitable type adapted to force grout through flexible conduits and into the voids and interstices between individual particles of aggregate in the cavity. It is generally preferable to use a positive displacement type pump so that the quantity of grout being forced into the structure can be controlled and regulated.

As shown in the drawings a plurality of pumps in tandem carried by a single frame may be utilized.

1f desired, the source of power utilized to drive the pumps may be provided with a Vspeed control for 'each individual pump for for certainl groupings of pumps and 'in this rmanner if a positive displacement type 'pum-p is used the `quantity of grout forced :from the particular pump or pumps may 'be closely controlled according to the selection of the operator. This .provides a Imeter-- ing eirect such that when certain portions of the structure require more grout, this may be obtained by speeding up the pumping in this loca tion. The .same eiect could be achieved by a larger number of grout casings and hose lines in the particular area but 'this requires additional vequipment .and can be as readily accomplished by controlling the speed of the pump.

The supply pipes I6 may supply grout to a header or manifold Hi which leads to the pumps disposed `at each particular pumping station. The grout passes through the pump and is forced Vunder pressure into ilegible hose lines I9 connected to the discharge port of the pump through valves 2i). The flexible hose lines I9 are adapted to be inserted into the casing members 8 to permit the grout to be supplied to the cavity. Each of the casing members has apertures or slits 2| in its exterior wall to provide a passage for the grout to flow from the interior of the casing member into the cavity. These slits are placed at suitable intervals along the casing members.

The grouting is begun by inserting a predetermined number of ilexible lines in the casing members 8 and selectively controlling the number and location of the flexible hose lines to be used for carrying grout so that the approximately correct amount of grout will be placed through- Y' out the cavity to provide a progressively rising horizontal grout level. As grouting progresses the hose lines through which grout is being pumped may be turned 01T or Vchanged in loca tion to meet the needs as determined by the size and shape of the cavity.

To facilitate control, lines may be dropped into those of the casing members which are not in use and for this purpose a testing element of any suitable size and shape may be provided and secured to the end of a suitable line and dropped into one of the casing members 8. Preferably such testing element should have sucient weight to pass through water but not to penetrate grout. In this manner the grout levels in the casing may be determined in any desired portion of the structure and grouting can therefore be closely controlled.

The use of the closed conduit i4 insures that grout is being supplied to all of the stations since the conduit is designed to carry suilcient grout therethrough and provide a slight excess which will be returned to the reservoir l I. Means may be provided at each of the pumping stations to insure that the grout is being received and passed through the pump and into the hose lines. For example, a portion of the intake line may be made lof a transparent material or the supply pipes i6 may discharge into open hoppers which in turn lead into the pumps l5.

The ends of the hose lines are always maintained beneath the surface of the grout level to provide a seal for the end of the hose line to cause the grout to flow into the cavity. As the grout level rises the hose lines may be withdrawn so long as they are kept immersed in the liquid grout.

After the grouting has been completed the holes into the structure through which grouting ymay be accomplished, are blocked With suitable plugs and the grout permitted to set. In carrying out vthe invention as shown in the drawings with the use of the casing members 8, it is preferable to leave these casings inplace in the structure and they will have the eiect of adding reinforcing thereto. However, it may be advisable to utilize removable casings or to perform the grouting by immersing the conduits through which the grout is supplied in the cavity prior to filling with aggregate so that when the 'grouting has been done the structure will be complete except for any necessary surfacing.

The selection of the ingredients to be used in the grouting composition `are not a part of the present invention. From the practical standpoint, however, it is preferable to utilize a grout which constitutes a relatively stable suspension 'so that it may be pumped through substantial distances of piping or hose lines without separation of the ingredients. it should also have the capacity for being forced through the relatively ne voids and interstices in the cavity and opening into the' marginal portions of the cavity. Suitable grout compositions are disclosed in my Patents 2,313,107, 2,313,110 and 2,434,302. 'Such composition may comprise a mixture of a hydraulic cement, such as 'Portland cement, aluminous cement, etc., a. nely divided mineral filler or pozzolanic material, sand, water and a suspension stabilizing agent or a lubricant to provide a grout which is stable and capable of being pumped under pressure for long distances through .hose lines.

Examples of stabilizing agents or lubricants are the fatty acid glycerides, the fatty acids themselves, and salts and esters thereof, or protective' colloids which do not deleteriously affect the concrete. Cement dispersing agents such as calcium lignin sulphonate, condensation products of naphthalene sulfonic acid and formaldehyde, etc., may be utilized to increase the plasticity and owability of the grout. When it is desired to have the structure being fabricated more resistant to cycles of freezing and thawing, suitable air entraining agents may be utilized such as the alkali metal salts of fatty alcohol sulphates, Vinsol resin, the character of which is disclosed in the Hall Patent No. 2,221,546 and its use in cement is disclosed in the Bechtold et al. Patent No. 2,225,149.

It is also usually desirable to incorporate ingredients which will provide a slight expansion of the grout composition during setting thereof so that after it has been forced in place it will securely bond to the aggregate, permanent rock, concrete or masonry walls, etc., and provide a solid dense structure. Finely divided aluminum will liberate gas during the setting of the grout which is effective to cause such expansion and is preferably present in the grout composition.

Thus, it may be seen that by the present invention erection of any desired structure or portion thereof may be accomplished in a selectively controlled manner with the grouting carried on continuously to obtain a more nearly true monolithic structure without joints between the various portions thereof. Furthermore, in the case of additions to existing structures, the addition will be rmly bonded and secured to the original structure, and/or to rock or earth bounding the cavity which defines the addition.

The use of a supply conduit for the grout which returns to the grout supply is usually a desirable feature in insuring that all stations are `continuously supplied With grout. If a single grout supply line without a return be utilized, and one or more stations in the region of the grout supply draw a substantial portion of the grout from the supply line, it is possible that the portions of the supply line beyond such stations may plug due to little or no flow of grout in such portions of the line. However, it is not always advantageous to provide a return run of the grout conduit to the mixer, as the supply lines may readily withdraw the grout flowing through the conduit.

The use of a multicylinder pump, or a plurality of pumps driven in tandem, is also highly advantageous since all of the grout lines from that pumping station Will ow evenly and each will force a uniform quantity of grout into the area of the cavity which they serve. lf conditions should cause one of the lines to plug, the stopping of one of the pumps, or one of the cylinders, would cause stalling of the balance of the pumps at that pumping station and would indicate the trouble to the operator immediately.

The present invention has been found especially advantageous since structures built in accordance therewith may be grouted with relatively low pressures and still obtain substantially complete filling of all voids in the cavity or openings into the cavity, resulting in a solid dense structure with very low shrinkage upon setting of the grout. By providing numerous grouting supply lines in the structure to be grouted and using a plurality of pumps, a large volume of grout may be supplied so that the cavity to be grouted can be lled relatively rapidly and more completely even though the individual grout lines are operated with relatively low pressure. It is essential to consider the strength of the surfaces defining the cavity since the grouting pressure must be sufciently low so that these defining surfaces will not be damaged.

While the present invention has been described primarily in connection with the grouting of prepared cavities containing aggregate enclosed by defining surfaces, it will be obvious that it may be equally well applied to the grouting of porous masses having voids and interstices which may occur naturally and may or may not be enclosed by defining surfaces acting as a form. Examples of such applications where the present invention may be utilized with excellent results are the grouting of rock masses utilized for breakwalls, jetties, and the like, where it is desired to solidify and densify such porous masses. Porous earth strata, foundations, or faulty concrete structures having voids and interstices therein may also be beneficially treated by the present invention.

It is to be understood that variations and modifications of the specic steps of the process and embodiments of the apparatus herein shown and described for purposes of illustration, may be made without departing from the spirit of the invention.

What I claim is:

1. In the process of constructing a monolithic concrete structure by confining a mass of aggregate between surfaces which define the desired structure and forcing grout under pressure from a remote mixing station into said aggregate to ll the voids and interstices therein, the improvement which comprises pumping the grout along a closed path having a delivery section leading from said remote mixing station to adjacent said mass of aggregate and a return section leading back to the mixing station, withdrawing grout at a plurality of points spaced along the delivery section of said closed path, and separately pumping the withdrawn grout from said spaced points through separate distribution conduits and thence into spaced regions of said mass of aggregate, the amount of grout pumped from the mixing station through the delivery section of said closed path being greater than the amount withdrawn at said spaced points, and the excess being returned to the mixing station through the return section of said closed path.

2. In the process of constructing a monolithic concrete structure by preparing a cavity defining the boundaries of said structure, filling said cavity with a mass of aggregate, and forcing grout under pressure from a remote mixing station into said aggregate to fill the voids and interstices therein and form a monolithic mass of concrete, the improvement which comprises locating a plurality of grout intrusion conduits in said cavity for conveying grout to spaced regions therein according to a predetermined plan, pumping the grout along a closed path having a delivery section leading from said remote mixing station to adjacent said mass of aggregate and a return section leading back to the mixing station, withdrawing grout at 'a plurality of points spaced along the delivery section o said closed path, and separately pumping the withdrawn grout from each of said spaced points through separate distribution conduits and thence selectively through said grout intrusion conduits in a predetermined order and into said cavity to ll the voids and interstices in the mass of laggregate progressively according to said plan, the amount of grout pumped from the mixing station through the delivery section of said closed path being greater than the amount withdr-awn at said spaced points, and the excess being returned to the mixing station through the return section of said closed path.

3. In the process of constructing a monolithic concrete structure by preparing a cavity defining the boundaries of said structure, lling said cavity with a mass of aggregate, and conveying grout under pressure to spaced points distributed throughout the cavity according to a predetermined plan, the improvement which comprises pumping the grout lalong a closed path having a delivery section leading from said remote mixing station to adjacent said mass of aggregate and a return section leading back to the mixing station, withdrawing grout at 'a plurality of points spaced along the delivery section of said closed path, and separately pumping the withdrawn grout from said spaced points through separate distribution conduits land thence from each distribution conduit selectively to said spaced points in the cavity in a predetermined order to ll the voids and interstices in the mass of aggregate progressively according to said plan, the amounts of grout pumped from the mixing station through the delivery section of said closed path being greater than the amount withdrawn in said spaced points, and the excess being returned to the mixing stations through the return section of said closed path.

4. The process of claim 3 in which the amounts of grout pumped through said grout intrusion conduits are separately metered so that the total amount of grout pumped therethrough may be determined for ascertaining that substantially all the voids and interstices in a given region of said mass of aggregate have been lled.

5. In apparatus for pumping grout under pressure from a mixer to a mass of aggregate prepl'aced in a cavity, the combination comprising a grout mixer, a grout reservoir for receiving grout from said mixer, a main grout supply conduit leading along a closed path from said reservoir to adjacent said cavity and back to said reservoir, means for forcing a, continuous stream of grout under pressure from said reservoir through said grout supply conduit and back to said reservoir, a plurality of positive displacement pumps respectively connected to said main grout supply conduit at points spaced therealong for withdrawing grout therefrom, and at least one grout intrusion conduit connected to each of said pumps for conveying the withdrawn grout to different regions in said cavity, whereby a continuous iow of grout through said main grout supply conduit may be maintained while the withdrawal of grout by said pumps is varied or suspended, and the total flow of grout to said cavity through the plurality of grout distribution conduits may be metered.

6. In apparatus for pumping grout under pressure from a, mixer to a mass of aggregate preplaced in a cavity, the combination defined in claim in which each of said positive displacement pumps includes a plurality of pumping units driven mechanically'` from a common drive, and in which a single grout distribution conduit is connected to each unit thereof, whereby grout will be forced in predetermined relative proportions through all of the grout distribution oonduits connected to a given pump.

'7. In apparatnus for pumping grout under pressure from a mixer to a mass of aggregate preplaced. in a cavity, the combination .comprising a, grout mixer, a grout reservoir for receiving grout from said mixer, a main grout supply conduit leading along the closed path from said reservoir to adjacent said cavity and back to said reservoir, means for forcing a continuous stream of grout under pressure from said reservoir through said grout supply conduit and back to said reservoir, a positive displacement pump connected to said main grout supply conduit for withdrawing grout therefrom, said positive displacement puinp including a, plurality of matched pumping units driven at the same rate by a common drive, and a corresponding plurality of grout distribution conduits respectively connected to each unit of said pump, whereby equal quantities of grout will be forced through all of said grout distribution conduits.

LOUIS S. WERTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,313,109 Wertz Mar. 9, 1943 2,313,110 Wertz Mar. 9, 1943 

